Ok, So i'm swapping removable hard drives around my systems trying to get that nazi Win2k installed, and now I've placed a hard disk with Windows XP on it back into it's orginal machine (it never went into another machine) and all of a sudden it won't boot. I get: Invalid system disk Replace the disk, and then press any key arg! I can boot from a floppy and see the drive (C and all the files on it, it just seems to have lost its system boot files. Anyone know how to sys a Windows XP drive? UPDATE: - FDISK /mbr did not work. - The partion with XP on it is the primary, it's active, and FAT32.